This study aimed to evaluate the effectiveness of polymeric materials used in the manufacture of thin plastic membranes as liners for domestic wastewater wells (black wells) as a temporary solution until the completion of sewerage infrastructure. The research methodology was based on an experimental approach that included analyzing the physical and chemical properties of the materials used and testing their performance under realistic environmental conditions. The study also assessed these materials' insulation capability, their ability to prevent fluid and odor leakage, and their resilience to environmental stresses and challenges. The study focused on two main applications: first, the use of a geoplastic membrane made of high-density polyethylene to isolate leachate generated from fast-food restaurant waste sites, due to its high resistance to volatile acids. Second, the application of composite plastic liners made of low-density polyethylene with carefully measured proportions of linear low-density polyethylene to line domestic wastewater wells. The results demonstrated the effectiveness of these materials in preventing contaminated water from leaking into the soil, reducing unpleasant odors, and ensuring the stability and durability of the liner under harsh environmental conditions. These findings highlight the importance of using polymeric materials as an innovative and effective solution to improve wastewater management and mitigate its environmental impact, with potential for developing more sustainable applications in the future......................... Keywords: ..............Polymeric materials, plastic covers, black wells, effective isolation.